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Old 17 March 2009, 02:37   #1
Supamax
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Sorry, Dungeon Master again :)

I read somewhere on the board that DM's protection (and Chaos Strikes Back's too) is based on weak bits.

I was wondering... is there a SPS game with weak bits protection on the same track as DM (Track 0 Side 1) ?

EDIT: I admit I don't have a clue about how it is possible to make a protection which causes a different read any time

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Old 17 March 2009, 10:03   #2
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EDIT: I admit I don't have a clue about how it is possible to make a protection which causes a different read any time
You can think of it kinda like unformatted tracks. Each time the track is read the controller returns some random values which are different when the track is read repeatedly. When the game does its disk check if all reads produce the same data then it knows that it's a copy
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Old 17 March 2009, 17:16   #3
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Quote:
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You can think of it kinda like unformatted tracks. Each time the track is read the controller returns some random values which are different when the track is read repeatedly. When the game does its disk check if all reads produce the same data then it knows that it's a copy
Hi,
I thought it could be something like that; however, DM will recognize the difference between an unformatted track and a track with weak bits.
Can we tell that a track with weak bits is something like a partially unformatted track? I suppose it's much more difficult than this .
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Old 17 March 2009, 17:29   #4
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You can think of it kinda like unformatted tracks.
Spot the key word Although this is mostly for the ST maybe this can explain it better for you http://dmweb.free.fr/?q=node/210
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Old 17 March 2009, 17:38   #5
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WOW, great link!
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Old 17 March 2009, 17:54   #6
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I seem to remember, though, that other games with weak bits were correctly dumped by SPS (but I could be wrong).
If so, why DM's weak bits are so "special"? Why isn't it possible (yet) to correctly get a SPS image of it?
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Old 18 March 2009, 01:24   #7
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it's ATARI ST weak bits ! Not amiga ones that's why !
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Old 18 March 2009, 01:26   #8
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it's ATARI ST weak bits ! Not amiga ones that's why !
What do you mean exactly?
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Old 18 March 2009, 03:45   #9
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the protected track is an atari ST one, with weak bits.

Remember, the amiga is able to read ST, PC, mac disk format
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Old 18 March 2009, 03:58   #10
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Remember, the amiga is able to read ST, PC, mac disk format
Hi Denis,

Could you please elaborate on this?

Thanks,

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Old 19 March 2009, 04:52   #11
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simple : The protection track on the amiga version of dungeon master is an atari ST track.
Pure and simple. And this one use Weak bits

The amiga has abilities to read non amiga formats. you must tell it how to read those
tracks. The amiga has even hardware facilities to read GCR macintosh disks (as stated in
the amiga disk drive book).
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